Genesis 1:14
12 The land produced vegetation—plants yielding seeds according to their kinds, and trees bearing fruit with seed in it according to their kinds. God saw that it was good. 13 There was evening, and there was morning, a third day. 14 God said, “Let there be lights in the expanse of the sky to separate the day from the night, and let them be signs to indicate seasons and days and years, 15 and let them serve as lights in the expanse of the sky to give light on the earth.” It was so.
Jubilees 2:9
8 On the fourth day the Lord made the sun, the moon, and the stars. He placed them in the heavenly firmament to shine on the whole earth, to rule over day and night, and to separate between light and darkness. 9 The Lord appointed the sun as a great sign above the earth for days, sabbaths, months, festivals, years, sabbaths of years, jubilees, and all times of the years. 10 It separates between light and darkness and serves for wellbeing so that everything that sprouts and grows on the earth may prosper. These three types he made on the fourth day.
Notes and References
"... Genesis had said that God created the sun and the moon “to serve as signs for the set times, the days and the years” (Genesis 1:14). But this potentially implied that the moon had some role in establishing when festivals would occur, as well as in determining the length of the year. Both Jubilees’ original author and the Interpolator endorsed a calendar in which the moon had no role: a “month” was simply an arbitrary 30-day unit entirely independent of the phases of the moon. (The Interpolator further specifies that the official year contains exactly 364 days—it is not clear what the original author thought) So Jubilees’ author here is at pains to stress that Genesis 1:14 was actually intended to say that the sun alone would determine the “months, festivals, years” ..."
Kugel, James L. A Walk through Jubilees: Studies in the Book of Jubilees and the World of Its Creation (p. 31) Brill, 2012